Haines, A.J. 1978 Local magnitudes for New Zealand earthquakes. [s.l.]: [s.n.]. Report / Geophysics Division 132 15 p.
Abstract: Richter's precise definition of local earthquake magnitude is too restrictive to apply under New Zealand conditions. This report describes new procedures for assigning magnitudes in New Zealand, based on a modified definition and derived from amplitude-distance relations determined directly from New Zealand earthquakes. For all crustal earthquakes, and for subcrustal earthquakes in or north of the Main Seismic Region, the magnitudes produced are appropriate to head-wave propagation, whereas for subcrustal earthquakes south of the Main Seismic Region they are appropriate to body-wave propagation. The only times inelastic attenuation has to be allowed for is with subcrustal earthquakes south of the Main Seismic Region and when paths from crustal earthquakes pass through a region which includes the zone of recent volcanism in the centre of the North Island